New Gaia binary star measurements seem to support MOND and challenge dark matter

Yes, I read the report at phys.org too. Reference paper, Ref - Breakdown of the Newton–Einstein Standard Gravity at Low Acceleration in Internal Dynamics of Wide Binary Stars, https://iopscience.iop.org/article/10.3847/1538-4357/ace101, 24-July-2023. “Abstract A gravitational anomaly is found at weak gravitational acceleration gN ≲ 10^−9 m s^−2 from analyses of the dynamics of wide binary stars selected from the Gaia DR3 database that have accurate distances, proper motions, and reliably inferred stellar masses...A gravitational anomaly parameter δobs−newt between the observed acceleration at gN and the Newtonian prediction is measured to be: δobs−newt = 0.034 ± 0.007 and 0.109 ± 0.013 at gN ≈ 10^−8.91 and 10^−10.15 m s^−2, from the main sample of 26,615 wide binaries within 200 pc. These two deviations in the same direction represent a 10σ significance. The deviation represents a direct evidence for the breakdown of standard gravity at weak acceleration. At gN = 10^−10.15 m s^−2, the observed to Newton-predicted acceleration ratio is . This systematic deviation agrees with the boost factor that the AQUAL theory predicts for kinematic accelerations in circular orbits under the Galactic external field.”

The phys.org report does state: "The weak-acceleration catastrophe of gravity may have some similarity to the ultraviolet catastrophe of classical electrodynamics that led to quantum physics. Wide binary anomalies are a disaster to the standard gravity and cosmology that rely on dark matter and dark energy concepts. Because gravity follows MOND, a large amount of dark matter in galaxies (and even in the universe) are no longer needed. This is also a big surprise to Chae who, like typical scientists, "believed in" dark matter until a few years ago…Pavel Kroupa, professor at Bonn University and at Charles University in Prague, has come to the same conclusions concerning the law of gravitation. He says, "With this test on wide binaries as well as our tests on open star clusters nearby the sun, the data now compellingly imply that gravitation is Milgromian rather than Newtonian. The implications for all of astrophysics are immense."

I am amazed at the accelerations reported expressed in meters/second and distances out to some 200 pc or about 652 light-years using 26,615 wide binaries. It will be interesting to see what others measure and declare here as time goes by.
 
They have distance, proper motion and "inferred mass". From that they calculate orbital period, then compare to actual. The discrepancy is due to MOND
A problem I see is the orbit period is used to determine mass. Then that is used to infer an ideal orbital period. Isn't this a circular argument?
 
They have distance, proper motion and "inferred mass". From that they calculate orbital period, then compare to actual. The discrepancy is due to MOND
A problem I see is the orbit period is used to determine mass. Then that is used to infer an ideal orbital period. Isn't this a circular argument?
Bill, I haven't tried to review the logic or math, so all I can speculate is that they did the usual mass inferences and then showed that there was a systematic problem with the results when the gravitational acceleration was very small. The article speaks of "wide binaries follow highly elongated orbits", so there may be some differences from Newtonian and Relativistic predictions of the apparent accelerations when the binary pairs are widely separated, compared to when they are more closely approaching each other? But, considering the data was collected during what could only be a very small part of the orbits of such widely separated stars, it does leave me wondering.

My thoughts were more along the line that there may be some sort of small systematic error in their process which only dominates the results when the gravitational acceleration is very small. They claim high confidence levels, but my experience has been that the uncertainty levels of most model results are generally underestimated.

The article states "I have also released all my codes for the sake of transparency and to serve any interested researchers." So, I will just wait to see what the experts in this field can find in the documentation.

Whatever the results of expert reviews and attempts at replication, this paper seems to have only the prospects for providing an important revelation to our understanding of gravity, or a grave egg-on-the-face moment for the researchers who claim such high confidence.
 
Here is the problem:
I assume they use the speed of the orbit to tell them what the mass of the system is. I don't know how else to do it.
Then they use the mass of the system to tell them what the orbit should be.
Then they compare to actual.
Not enough independent variables.
They must have some other way of determining mass. Like maybe knowing the age of a star and how bright it is tells them mass. I don't know. I can't decipher the article.
 
BIll, I understand what you are saying. But, if they properly use the available info to compute their parameters, I would expect the results to match the theories used to make those computations, so there should be a verification of Newtonian or Relativistic theory, right? The fact that they are claiming non-agreement for specific parts of the orbits, where gravity acceleration is very low, seems to me to imply that there is something different somewhere. If it was only "circular logic", I would expect only agreement, rather than some non-agreement.
 
I agree, circular logic would be identical. They must have another way of measuring mass. However, the differences they find are extremely small. They have error bars allright, but I am thinking back about the vanishing amount of excess heat they saw in cold fusion 30 years ago. It kept getting smaller and smaller. I also have a problem with it appearing only at very small g forces, coincidentally the same place the measurements are so tiny and fraught with potential sources of error.
Now I hear there are galaxies with no dark matter, no anomalous differential rotation problem. It gets more confusing.
 
If "dark matter" is simply regular matter that is not radiating photons (which was sort of the original idea), then it wouldn't be illogical for some galaxy to have a much larger than normal portion of its regular matter emitting radiation if there was some perturbation from whatever controls "average". Or, if dark matter really is something other than regular matter, then there may be different attractive or repulsive processes that could separate the two. I am not so sure that the measurements being made are really good enough to say there is zero dark matter in some galaxy, or what fraction of the galaxy's mass is emitting radiation we can detect.

It is just interesting to find something that is not already "explained" (rightly or wrongly) by the current theories, so that people really need to open their minds and think. That is how we make progress.
 
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Knowing next to nothing about MOND or dark matter I can innocently ask how it is that-
If some galaxies do not display Dark Matter symptoms -
We apply solutions to those that do without explaining why there are major exceptions!
Surely any theory should account for both 'conditions'
What am I missing? Mostly.
 
Gibsense, The whole "dark matter" thing is an attempt to explain observations that we do not understand. And there are lots of attempts to form explanations, using some extremely different conceptual approaches.

"Dark matter" is just one of the approaches, postulating that there is some sort of matter there that we just don't see. That is general concept is divided into all sorts of possibilities for that matter being everything from "black holes" of various sizes to sub-atomic particles that we have not yet learned to detect. And, it doesn't have to be just one type of matter that we can't detect - some have proposed that there is a whole universe of dark elements and dark photons that we can't detect, interacting within the "dark" realm similarly to what we see with regular matter.

MOND is a wholly different approach, trying to modify Newtonian Gravity Theory to fit the observations.

And I have seen statements that better accounting for "frame dragging" of space by rotating masses in General Relativity Theory can fit the observations.

So, if it doesn't make sense to you, you actually do understand the situation.

Nobody is currently making sense of all of our observations. The best they can do is to postulate unproven things like matter we can't see and energy we can't detect or predict - so that the theorists have a bunch of "free parameters" that they can adjust to make their calculations match the observations. But, that proves nothing - until some of those theories make predictions that can be tested to see if they match observations that they have not already been fitted to match.

So far, General Relativity Theory has done an excellent job of matching predictions. But, the "Big Bang Theory" is not consistent with General Relativity Theory unless a lot of mass and energy that we can't explain is added. 95% of the mass and energy needed to make the BBT work mathematically is stuff we have not been able to detect or prove to really exist.
 
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Interesting that some galaxies have dark matter and some do not. Presumably, the differences between the two may hold clues as to what Dark Matter is.
  1. Galaxies without dark matter are significantly less 'dense'; the theory is that they have had an encounter with other galaxies resulting in disruption.
  2. I suggest that as a result, the gravity well the galaxy sits in will be less deep
  3. The dilation effects will therefore be less apparent
A quote from my research ". Galaxies without dark matter are more isolated and simple, and they have less star formation and evolution. galaxies without dark matter can result from collisions with larger galaxies, which strip away most of their material, leaving behind only stars and some residual dark matter"

The General Relativity solution to dark matter then would be my bet. I must check but if I remember correctly it was a time-dilation-type solution or maybe it was simply a dilation of time and distance due to gravitation (a deep well)
 
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I have just found this part of an article on the Net

"Ultimately, using the effects of time dilation is a novel approach to trying to understand the nature of Dark Matter and the accelerating expansion of the universe, and something that has never been tried before.

“[Previously] we only knew how to measure the speed of celestial objects and the sum of the distortion of time and space,” explained Bonvin, although now he says “we have developed a method for accessing this additional measurement, and it’s a first.”

Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on Twitter, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org. "

I am astounded by the statement that Time Dilation effects "have never been tried before". If someone as ignorant as myself can deduce that it is an obvious "maybe" then what on Earth are the boffins playing at? In itself, that becomes an issue I think. I wonder why that is.
 
Ii have been posting for years that we should think about the potential for time dilation if we are considering the universe to have more concentrated matter in the past. The usual response is "dilation compared to what?" using the assumption that the universe has always been approximately homogeneous and there is nothing outside the universe to be compared to.

But, there is also the problem that the homogeneity of the universe is theorized to be due to the ability of light to travel across it in very short time periods while it was just a tiny universe less than what we think of as the size of an atom, today. The problem with that is General Relativity Theory tells us that all observers will measure the speed of light to be the same value, using their measures of length and time. SO, even if "inflation" is true, then the uninflated meter sticks and the uninflated seconds available to hypothetical observers in the infant universe should still have measured the speed of light to be unable to transit the dimension of the early universe sufficiently rapidly to maintain its homogeneity.

The BBT is just internally inconsistent with its hypotheses. To make it work mathematically, it needs to violate General Relativity Theory in multiple ways at multiple points in the evolution of the universe, without any real basis for why that would have happened - except that it had to happen that way for the theory to avoid being disproven.
 
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Is this thought significant?
If a light year and a year are equivalent (and interchangeable mathematically) then if you were subjected to rapid spatial expansion you would not notice. Time, your time, would still be dependent on the distance your space expanded. Physics would continue at 'c'.
You would need to be separated from the rapid spatial expansion to see it for what it is. The separation can be either in space or in time.
Therefore during inflation physics ('c') would continue 'normally'. Only when observed later would the rapid expansion be seen for what it was/is.
I don't know if this addresses any of the issues in your second paragraph above does it?
 
Yes,that is what I was saying. The problem with the BBT is that it does not act like that. I has the perspective of being "outside the universe" and thinking that light could traverse the universe in an instant before the universe "inflated".

Not really a surprising oversight, considering that the BBT is formulated by particle physicists viewpoints instead of astronomers viewpoints until th expansion of the universe gets to where there are some actual astronomy observations.
 
I agree, circular logic would be identical. They must have another way of measuring mass. However, the differences they find are extremely small. They have error bars allright, but I am thinking back about the vanishing amount of excess heat they saw in cold fusion 30 years ago. It kept getting smaller and smaller. I also have a problem with it appearing only at very small g forces, coincidentally the same place the measurements are so tiny and fraught with potential sources of error.
Now I hear there are galaxies with no dark matter, no anomalous differential rotation problem. It gets more confusing.
Maybe circular argument with a subtle roundoff error or truncation in the computations, giving the (very, very small) deviation. Fun story. I was in my doctoral advisor's office one Friday aft, waiting to go to the campus pub, waiting for him to finish with a first year student. She had the wrong answer to a problem, yet neither could figure out what she did wrong with her method. He then asked her what answer she got, and after shuffling a couple papers, she quoted 49.9999999 whatevers. He sagged like a rhino taking a bullet. He then ventured to tell her that that was VERY close to 50, the correct answer as quoted in the textbook. You could tell the number of digits in her calculator display from her answer.
 

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